A second look at fast pyrolysis of biomass - the RTI process

Over the past two decades a great deal of experimental work as been carried out on the development of fast pyrolysis processes, particularly for bioma ss and for lignocellulosic waste materials. High yields of an organic liqui d product (50-70%) are typical of atmospheric pressure short contact time p yrolysis of such feedstocks. This liquid product has been shown to be usabl e both as an alternative liquid fuel, and as a chemical feedstock because o f its content of significant concentrations of potentially useful organic c hemicals. The characteristics of the more important fast pyrolysis processe s are reviewed, and the advantages and problems existing with present pyrol ysis reactors are discussed, with the emphasis on bubbling fluidized bed sy stems. Experience with the process has led us to a somewhat different view of the optimal conditions for fast pyrolysis, and has resulted in the recen t development of a new fluid bed process-the RTI Process. Characteristics o f the RTI process are described and its advantages over existing fast pyrol ysis technologies summarized. (C) 1999 Elsevier Science B.V. All rights res erved.